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Georgia Tech
1.
Doroski, Derek M.
The effects of tensile loading and extracellular environmental cues on fibroblastic differntiation and extracellular matrix production by mesenchymal stem cells.
Degree: PhD, Biomedical Engineering, 2011, Georgia Tech
URL: http://hdl.handle.net/1853/39523 
► Ligament/tendon tissue engineering has the potential to provide therapies that overcome the limitations of incomplete natural healing responses and inadequate graft materials. While ligament/tendon fibroblasts…
(more)
▼ Ligament/tendon tissue engineering has the potential to provide therapies that overcome the limitations of incomplete natural healing responses and inadequate graft materials. While ligament/tendon fibroblasts are an obvious choice of cell type for these applications, difficulties associated with finding a suitable cell source have limited their utility. Mesenchymal stem cells/marrow stromal cells (MSCs) are seen as a viable alternative since they can be harvested through routine medical procedures and can be differentiated toward a ligament/tendon fibroblast lineage. Further study is needed to create an optimal biomaterial/biomechanical environment for ligament/tendon fibroblastic differentiation of MSCs. The overall goal of this dissertation was to improve the understanding of the role that biomechanical stimulation and the biomaterial environment play, both independently and combined, on human MSC (hMSC) differentiation toward a ligament/tendon fibroblast phenotype. Specifically, the effects of cyclic tensile stimuli were studied in a biomaterial environment that provided controlled presentation of biological moieties. The influence of an enzymatically-degradable biomaterial environment on hMSC differentiation was investigated by creating biomaterials containing enzymatically-cleavable moieties. The role that preculture may play in tensile responses of hMSCs was also explored. Together, these studies provided insights into the contributions of the biomaterial and biomechanical environment to hMSC differentiation toward a ligament/tendon fibroblast phenotype.
Advisors/Committee Members: Temenoff, Johnna (Committee Chair), Boyan, Barbara (Committee Member), Garcia, Andres (Committee Member), Levenston, Marc (Committee Member), Lyon, Andrew (Committee Member).
Subjects/Keywords: GGGLGPAGGK; Matrix metalloproteinase; Oligo(poly(ethylene glycol) fumarate); Hydrogel; Mesenchymal stem cells Differentiation; Ligament prostheses; Tendons; Tissue engineering; Biomechanics
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APA (6th Edition):
Doroski, D. M. (2011). The effects of tensile loading and extracellular environmental cues on fibroblastic differntiation and extracellular matrix production by mesenchymal stem cells. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/39523
Chicago Manual of Style (16th Edition):
Doroski, Derek M. “The effects of tensile loading and extracellular environmental cues on fibroblastic differntiation and extracellular matrix production by mesenchymal stem cells.” 2011. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/39523.
MLA Handbook (7th Edition):
Doroski, Derek M. “The effects of tensile loading and extracellular environmental cues on fibroblastic differntiation and extracellular matrix production by mesenchymal stem cells.” 2011. Web. 15 Jan 2021.
Vancouver:
Doroski DM. The effects of tensile loading and extracellular environmental cues on fibroblastic differntiation and extracellular matrix production by mesenchymal stem cells. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/39523.
Council of Science Editors:
Doroski DM. The effects of tensile loading and extracellular environmental cues on fibroblastic differntiation and extracellular matrix production by mesenchymal stem cells. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/39523
Georgia Tech
2.
Soon, Allyson Shook Ching.
Exploiting fibrin knob:hole interactions for the control of fibrin polymerization.
Degree: PhD, Biomedical Engineering, 2011, Georgia Tech
URL: http://hdl.handle.net/1853/45917
► The minimization of blood loss represents a significant clinical need in the arena of surgery, trauma, and emergency response medicine. Fibrinogen is our body's native…
(more)
▼ The minimization of blood loss represents a significant clinical need in the arena of surgery, trauma, and emergency response medicine. Fibrinogen is our body's native polymer system activated in response to tissue and vasculature injury, and forms the foundation of the most widely employed surgical sealant and hemostatic agent. Non-covalent knob:hole interactions are central to the assembly of fibrin that leads to network and clot formation. This project exploits these affinity interactions as a strategy to direct fibrin polymerization dynamics and network structure so as to develop a temperature-triggered polymerizing fibrin mixture for surgical applications.
Short peptides modeled after fibrin knob sequences have been shown to alter fibrin matrix structure by competing with native fibrin knobs for binding to the available holes on fibrinogen and fibrin. The fusion of such knob peptides to a non-native component should facilitate binding of the fused component to fibrinogen/fibrin, and may permit the concomitant modification of the fibrin matrix. We examined this hypothesis in a three-step approach involving (a) analyzing the ability of tetrapeptide knob sequences to confer fibrin(ogen) affinity on a non-fibrin protein, (b) investigating the effect of knob display architecture on fibrin(ogen) structure, and (c) designing a temperature-responsive knob-displaying construct to modulate fibrin(ogen) affinity at different temperature regimes, thus altering fibrin(ogen) structure.
Advisors/Committee Members: Barker, Thomas (Committee Chair), Chaikof, Elliot (Committee Member), Collier, Joel (Committee Member), Lyon, Andrew (Committee Member), Temenoff, Johnna (Committee Member).
Subjects/Keywords: Protein; Self-assembling; Polyethylene glycol; Fibrinogen; Elastin; Hematologic agents; Hemostatics; Hemorrhage; Proteins; Protein binding; Biomolecules
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APA (6th Edition):
Soon, A. S. C. (2011). Exploiting fibrin knob:hole interactions for the control of fibrin polymerization. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/45917
Chicago Manual of Style (16th Edition):
Soon, Allyson Shook Ching. “Exploiting fibrin knob:hole interactions for the control of fibrin polymerization.” 2011. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/45917.
MLA Handbook (7th Edition):
Soon, Allyson Shook Ching. “Exploiting fibrin knob:hole interactions for the control of fibrin polymerization.” 2011. Web. 15 Jan 2021.
Vancouver:
Soon ASC. Exploiting fibrin knob:hole interactions for the control of fibrin polymerization. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/45917.
Council of Science Editors:
Soon ASC. Exploiting fibrin knob:hole interactions for the control of fibrin polymerization. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/45917
Georgia Tech
3.
Chen, Vincent W.
Fabrication and chemical modifications of photonic crystals produced by multiphoton lithography.
Degree: PhD, Chemistry and Biochemistry, 2011, Georgia Tech
URL: http://hdl.handle.net/1853/45918
► This thesis is concerned with the fabrication methodology of polymeric photonic crystals operating in the visible to near infrared regions and the correlation between the…
(more)
▼ This thesis is concerned with the fabrication methodology of polymeric photonic crystals operating in the visible to near infrared regions and the correlation between the chemical deposition morphologies and the resultant photonic stopband enhancements of photonic crystals.
Multiphoton lithography (MPL) is a powerful approach to the fabrication of polymeric 3D micro- and nano-structures with a typical minimum feature size ~ 200 nm. The completely free-form 3D fabrication capability of MPL is very well suited to the formation of tailored photonic crystals (PCs), including structures containing well defined defects. Such structures are of considerable current interest as micro-optical devices for their filtering, stop-band, dispersion, resonator, or waveguiding properties. More specifically, the stop-band characteristics of polymer PCs can be finely controlled via nanoscale changes in rod spacings and the chemical functionalities at the polymer surface can be readily utilized to impart new optical properties.
Nanoscale features as small as 65 ± 5 nm have been formed reproducibly by using 520 nm femtosecond pulsed excitation of a 4,4'-bis(di-n-butylamino)biphenyl chromophore to initiate crosslinking in a triacrylate blend. Dosimetry studies of the photoinduced polymerization were performed on chromophores with sizable two-photon absorption cross-sections at 520 and 730 nm. These studies show that sub-diffraction limited line widths are obtained in both cases with the lines written at 520 nm being smaller. Three-dimensional multiphoton lithography at 520 nm has been used to fabricate polymeric woodpile photonic crystal structures that show stop bands in the visible to near-infrared spectral region.
85 ± 4 nm features were formed using swollen gel photoresist by 730 nm excitation MPL. An index matching oil was used to induce chemical swelling of gel resists prior to MPL fabrication. When swollen matrices were subjected to multiphoton excitation, a similar excitation volume is achieved as in normal unswollen resins. However, upon deswelling of the photoresist following development a substantial reduction in feature size was obtained. PCs with high structural fidelity across 100 µm × 100 µm × 32 layers exhibited strong reflectivity (>60% compared to a gold mirror) in the near infrared region. The positions of the stop-bands were tuned by varying the swelling time, the exposure power (which modifies the feature sizes), and the layer spacing between rods.
Silver coatings have been applied to PCs with a range of coverage densities and thicknesses using electroless deposition. Sparse coatings resulted in enhanced reflectivity for the stop band located at ~5 µm, suggesting improved interface reflectivity inside the photonic crystal due to the Ag coating. Thick coatings resulted in plasmonic bandgap behavior with broadband reflectivity enhancement and PC lattice related bandedge at 1.75 µm. Conformal titania coatings were grown onto the PCs via a surface sol-gel method. Uniform and smooth titania coatings…
Advisors/Committee Members: Perry, Joseph (Committee Chair), Brédas, Jean-Luc (Committee Member), Lyon, Andrew (Committee Member), Srinivasarao, Mohan (Committee Member), Trebino, Rick (Committee Member).
Subjects/Keywords: Surface modification; Microfabrication; Photonic crystal; Two-photon; Photonics; Manufacturing processes; Photonic crystals; Nanostructured materials
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APA (6th Edition):
Chen, V. W. (2011). Fabrication and chemical modifications of photonic crystals produced by multiphoton lithography. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/45918
Chicago Manual of Style (16th Edition):
Chen, Vincent W. “Fabrication and chemical modifications of photonic crystals produced by multiphoton lithography.” 2011. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/45918.
MLA Handbook (7th Edition):
Chen, Vincent W. “Fabrication and chemical modifications of photonic crystals produced by multiphoton lithography.” 2011. Web. 15 Jan 2021.
Vancouver:
Chen VW. Fabrication and chemical modifications of photonic crystals produced by multiphoton lithography. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/45918.
Council of Science Editors:
Chen VW. Fabrication and chemical modifications of photonic crystals produced by multiphoton lithography. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/45918
Georgia Tech
4.
Smith, O'neil Lohanica.
Design and use of surface modifiers as tools for understanding and controlling interfaces in organic electronics.
Degree: PhD, Chemistry and Biochemistry, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/51838
► This thesis focuses on the use of surface modifiers as tools for probing and/or controlling interfaces. Surface modification of transparent conducting oxides (TCOs) with organic…
(more)
▼ This thesis focuses on the use of surface modifiers as tools for probing and/or controlling interfaces. Surface modification of transparent conducting oxides (TCOs) with organic and organometallic modifiers can be used as a tool for mediating interfacial energetics as well as probing the kinetics of charge-transfer at the metal oxide/organic interface. The synthetic tunability of these modifiers allows us to design molecules based on various parameters, which include the nature of the binding, spacer, and terminal groups. Based on this framework, several modifiers were synthesized and used to investigate surface energy tuning as well as charge injection kinetics as a function of molecular structure. More specifically, we use XPS/UPS to examine the evolution of the chemical structure and frontier orbital levels of the TCO/organic interface as a function of the chosen surface modifier. In addition, we investigate the impact that various molecular binding groups have on mediating the kinetics of charge-transfer.
In the last section of this body of work we examine the development of dielectric nanocomposite films for capacitor applications. More specifically, we examine the use of phosphonic acid modifiers to functionalize barium titanate nanoparticles in order to provide miscibility with a suitable polymer host. The effect of various modifiers on the dielectric properties not nanocomposite thin films was examined.
Advisors/Committee Members: Marder, Seth R. (advisor), Perry, Joseph W. (advisor), Lyon, Andrew (committee member), Sandhage, Kenneth (committee member), Tsukruk, Vladimir (committee member).
Subjects/Keywords: Surface modification; Organic electronics; Organic electronics; Interface circuits; Transparent electronics
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APA (6th Edition):
Smith, O. L. (2014). Design and use of surface modifiers as tools for understanding and controlling interfaces in organic electronics. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/51838
Chicago Manual of Style (16th Edition):
Smith, O'neil Lohanica. “Design and use of surface modifiers as tools for understanding and controlling interfaces in organic electronics.” 2014. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/51838.
MLA Handbook (7th Edition):
Smith, O'neil Lohanica. “Design and use of surface modifiers as tools for understanding and controlling interfaces in organic electronics.” 2014. Web. 15 Jan 2021.
Vancouver:
Smith OL. Design and use of surface modifiers as tools for understanding and controlling interfaces in organic electronics. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/51838.
Council of Science Editors:
Smith OL. Design and use of surface modifiers as tools for understanding and controlling interfaces in organic electronics. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/51838
Georgia Tech
5.
Douglas, Alison McKissock.
Engineering fibrin matrices for enhanced vascularization and cell infiltration.
Degree: PhD, Biomedical Engineering (Joint GT/Emory Department), 2015, Georgia Tech
URL: http://hdl.handle.net/1853/59111
► Wound healing and revascularization of tissues at sites of injury are fundamental problems in the field of regenerative medicine. One promising approach to supporting vascularization…
(more)
▼ Wound healing and revascularization of tissues at sites of injury are fundamental problems in the field of regenerative medicine. One promising approach to supporting vascularization is the use of fibrin polymers, the natural blood clotting protein, as an injectable biomaterial construct. Current fibrin matrices/sealants for wound healing applications use high concentrations of fibrinogen and thrombin, forming a dense matrix to facilitate stable clot formation. However, this limits the ability for endogenous cells to infiltrate the wound site for adequate tissue repair. The overall goal of this work is to design materials that are mechanically robust for ease of handling and clot stability, but allow for increased cell infiltration and tissue regeneration by modifying the fibrin network ultrastructure. This is achieved using colloidal assemblies of ultra low cross-linked poly(N-isopropylacrylamide) pNIPAm microgels (microgels), which we have shown can alter network architecture and mechanics. We hypothesized that by modifying microscale network structure we would enhance infiltrating cell motility, endogenous cell recruitment and angiogenesis, and tissue regeneration. Ultimately, it was shown that microgels enabled enhanced cell motility and infiltration in vitro, and in-growth of small diameter vessels in vivo. While, enabling larger vessel vascularization and multicellular processes involving collective cell migration still remain to be realized, this novel system represents a new method of modifying dense biomaterial systems for enhanced regenerative outcomes.
Advisors/Committee Members: Barker, Thomas H. (advisor), Fernandez-Nieves, Alberto (committee member), García, Andrés J. (committee member), Lyon, Andrew (committee member), Guldberg, Robert E. (committee member).
Subjects/Keywords: Fibrin; Microgels; Angiogenesis; Biomaterials; Cell migration; Infiltration
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APA (6th Edition):
Douglas, A. M. (2015). Engineering fibrin matrices for enhanced vascularization and cell infiltration. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59111
Chicago Manual of Style (16th Edition):
Douglas, Alison McKissock. “Engineering fibrin matrices for enhanced vascularization and cell infiltration.” 2015. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/59111.
MLA Handbook (7th Edition):
Douglas, Alison McKissock. “Engineering fibrin matrices for enhanced vascularization and cell infiltration.” 2015. Web. 15 Jan 2021.
Vancouver:
Douglas AM. Engineering fibrin matrices for enhanced vascularization and cell infiltration. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/59111.
Council of Science Editors:
Douglas AM. Engineering fibrin matrices for enhanced vascularization and cell infiltration. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/59111
Georgia Tech
6.
Gutowski, Stacie Marie.
Polymer coatings to improve host response to implanted neural electrodes.
Degree: PhD, Biomedical Engineering (Joint GT/Emory Department), 2014, Georgia Tech
URL: http://hdl.handle.net/1853/54007
► Neural electrodes are an important part of brain-machine interface devices that can restore functionality to patients with sensory and movement impairments including spinal cord injury…
(more)
▼ Neural electrodes are an important part of brain-machine interface devices that can restore functionality to patients with sensory and movement impairments including spinal cord injury and limb loss. Currently, chronically implanted neural electrodes induce an unfavorable tissue response which includes inflammation, scar formation, and neuronal cell death, eventually causing loss of electrode functionality in the long term. The objective of this research was to develop a coating to improve the tissue response to implanted neural electrodes. The hypothesis was that coating the surface of neural electrodes with a non-fouling, anti-inflammatory coating would cause reduced inflammation and a better tissue response to the implanted electrode. We developed a polymer coating with non-fouling characteristics, incorporated an anti-inflammatory agent, and engineered a stimulus-responsive degradable portion for on-demand release of the anti-inflammatory agent in response to inflammatory stimuli. We characterized the coating using XPS and ellipsometry, and analyzed cell adhesion, cell spreading, and cytokine release in vitro. We analyzed the in vivo tissue response using immunohistochemistry and microarray qRT-PCR. Although no differences were observed among the samples for inflammatory cell markers, lower IgG penetration into the tissue around PEG + IL-1Ra coated electrodes suggests an improvement in BBB integrity. Gene expression analysis showed higher expression of IL-6 and MMP-2 around PEG + IL-1Ra samples, as well as an increase in CNTF expression, an important marker for neuronal survival. An important finding from this research is the increased neuronal survival around coated electrodes compared to uncoated controls, which is a significant finding as neuronal survival near the implant interface is an essential part of maintaining electrode functionality.
Advisors/Committee Members: García, Andrés (advisor), Bellamkonda, Ravi (committee member), Gross, Robert (committee member), Lyon, Andrew (committee member), Stanley, Garrett (committee member).
Subjects/Keywords: Neural electrode; Polymer; PEG; Host response; Anti-inflammatory
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APA (6th Edition):
Gutowski, S. M. (2014). Polymer coatings to improve host response to implanted neural electrodes. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54007
Chicago Manual of Style (16th Edition):
Gutowski, Stacie Marie. “Polymer coatings to improve host response to implanted neural electrodes.” 2014. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/54007.
MLA Handbook (7th Edition):
Gutowski, Stacie Marie. “Polymer coatings to improve host response to implanted neural electrodes.” 2014. Web. 15 Jan 2021.
Vancouver:
Gutowski SM. Polymer coatings to improve host response to implanted neural electrodes. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/54007.
Council of Science Editors:
Gutowski SM. Polymer coatings to improve host response to implanted neural electrodes. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/54007
7.
Sathananthan, Saranya.
Modulating fibrin matrix properties via fibrin knob peptide functionalized microgels.
Degree: MS, Materials Science and Engineering, 2012, Georgia Tech
URL: http://hdl.handle.net/1853/44905
► Fibrin is the body's natural provisional matrix activated in response to vascular injury in which noncovalent knob:hole interactions between fibrin monomers lead to the assembly…
(more)
▼ Fibrin is the body's natural provisional matrix activated in response to vascular injury in which noncovalent knob:hole interactions between fibrin monomers lead to the assembly of fibrin for clot formation. In this study we aimed to exploit fibrin knob:hole affinity interactions with swelling, space filling microgels for the development of a potential bio-synthetic hybrid polymer system with hemostatic properties. Previous work has explored the inherent binding interactions of various fibrin knobs and their complementary polymerization holes, which have led to the development of fibrin knob peptide mimic (GPRPFPAC) with enhanced binding affinity for fibrin(ogen) holes. By coupling this enhanced fibrinogen binding peptide with a pNIPAm microgel system capable of being dynamically tuned and self-assembled, we hypothesized the specific and rapidly triggered formation of a bulk hydrogel in a wound environment (i.e. in the presence of fibrinogen). We found that at the peptide ligand density and concentrations of microgels used, that a rapid formation of a gel did not occur in the presence of fibrinogen alone. However with fibrinogen and thrombin, we found that fibrin network polymerization, structure, and viscoelastic properties were greatly altered in the presence of knob peptide-conjugated microgels.
Advisors/Committee Members: Barker, Thomas (Committee Chair), Lyon, Andrew (Committee Member), Milam, Valeria (Committee Member).
Subjects/Keywords: Fibrin knob peptides; Fibrin matrix properties; Microgels; Colloids; Fibrin; Tissue culture; Synthetic biology; Blood substitutes; Hematologic agents; Wound healing
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APA (6th Edition):
Sathananthan, S. (2012). Modulating fibrin matrix properties via fibrin knob peptide functionalized microgels. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/44905
Chicago Manual of Style (16th Edition):
Sathananthan, Saranya. “Modulating fibrin matrix properties via fibrin knob peptide functionalized microgels.” 2012. Masters Thesis, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/44905.
MLA Handbook (7th Edition):
Sathananthan, Saranya. “Modulating fibrin matrix properties via fibrin knob peptide functionalized microgels.” 2012. Web. 15 Jan 2021.
Vancouver:
Sathananthan S. Modulating fibrin matrix properties via fibrin knob peptide functionalized microgels. [Internet] [Masters thesis]. Georgia Tech; 2012. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/44905.
Council of Science Editors:
Sathananthan S. Modulating fibrin matrix properties via fibrin knob peptide functionalized microgels. [Masters Thesis]. Georgia Tech; 2012. Available from: http://hdl.handle.net/1853/44905
8.
Kincer, Matthew Ryan.
Polymeric templating and alignment
of fullerenes.
Degree: PhD, Materials Science and Engineering, 2011, Georgia Tech
URL: http://hdl.handle.net/1853/42879
► Fullerene research has advanced to elevated levels in a short period of time due to the unique chemical and physical properties of the caged molecule…
(more)
▼ Fullerene research has advanced to elevated levels in a short period of time due to the unique chemical and physical properties of the caged molecule that have been utilized in numerous applications. Due to the spherical shape of the fullerene molecule which allows for a hollow cavity, encapsulation of atoms or small molecules can occur within the ball structure. This encapsulation creates an endohedral component that is limited from interacting with other molecules which creates potential of control over electronic information of the isolated molecule. Endohedral fullerenes have the potential as serving as the base unit in a quantum computer if control over global alignment is attained. Thus, by using the inherent self-assembling capabilities of some organic materials, ordered endohedral fullerenes can be achieved. This dissertation investigates the ability to use self-assembling strategies to obtain alignment which include ordering within a morphologically controlled copolymer matrix, forming a supramolecular polymer complex with cyclodextrin, and encapsulation within the helical wrap of polymer chains. The ultimate goal is to understand the dynamics that control association and orientation of varying fullerene-based molecules in each strategy in order to maximize control over the final alignment of endohedral elements.
Advisors/Committee Members: Beckham, Haskell (Committee Chair), Bucknall, David (Committee Member), Lyon, Andrew (Committee Member), Srinivasarao, Mohan (Committee Member), Thio, Yonathan (Committee Member).
Subjects/Keywords: Star polymer; Electrospinning; Supramolecular complex; Fullerene; Fullerenes; Polymers Surfaces; Self-organizing systems; Quantum computers
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APA (6th Edition):
Kincer, M. R. (2011). Polymeric templating and alignment
of fullerenes. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/42879
Chicago Manual of Style (16th Edition):
Kincer, Matthew Ryan. “Polymeric templating and alignment
of fullerenes.” 2011. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/42879.
MLA Handbook (7th Edition):
Kincer, Matthew Ryan. “Polymeric templating and alignment
of fullerenes.” 2011. Web. 15 Jan 2021.
Vancouver:
Kincer MR. Polymeric templating and alignment
of fullerenes. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/42879.
Council of Science Editors:
Kincer MR. Polymeric templating and alignment
of fullerenes. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/42879
9.
Nguyen, Vu Anh.
Blends of Polydioctylfluorene (PFO) with polymeric and monomeric energy acceptors: correlation of fluorescence energy transfer and film morphology in breath figures and films.
Degree: PhD, Chemistry and Biochemistry, 2008, Georgia Tech
URL: http://hdl.handle.net/1853/24609
► Fluorescence energy transfer from poly(9,9-dioctylfluorene) to polymeric energy acceptors that include head-to-tail regioregular poly(3-hexylthiophene or P3HT) and poly(2-methoxy-5(2 -ethylhexyloxy)-1,4-phenylenevinylene) or MEH-PPV and monomeric acceptor meso-tetraphenylporphyrin…
(more)
▼ Fluorescence energy transfer from poly(9,9-dioctylfluorene) to polymeric energy acceptors that include head-to-tail regioregular poly(3-hexylthiophene or P3HT) and poly(2-methoxy-5(2 -ethylhexyloxy)-1,4-phenylenevinylene) or MEH-PPV and monomeric acceptor meso-tetraphenylporphyrin or TPP was studied and correlated with the underlying morphology when the donor-acceptor blends were prepared as drop-coated films or breath-figure structures. It was found that the phase-separate morphology in films and breath figures was influenced by a number of factors, including material transport dynamics, solubility of the blend components in a solvent, interaction of the solvent with the substrate, and the diffusion rate of the blend components.
Advisors/Committee Members: Tolbert, Laren (Committee Chair), Collard, David (Committee Member), Lyon, Andrew (Committee Member), Srinivasarao, Mohan (Committee Member), Wilkinson, Angus (Committee Member).
Subjects/Keywords: P3HT; MEH-PPV; PFO; Phase separation; Breath figures; Fluorescence energy transfer; TPP; Conjugated polymers; Electroluminescent devices; Optoelectronics; Thin films; Energy transfer; Phase partition
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APA (6th Edition):
Nguyen, V. A. (2008). Blends of Polydioctylfluorene (PFO) with polymeric and monomeric energy acceptors: correlation of fluorescence energy transfer and film morphology in breath figures and films. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/24609
Chicago Manual of Style (16th Edition):
Nguyen, Vu Anh. “Blends of Polydioctylfluorene (PFO) with polymeric and monomeric energy acceptors: correlation of fluorescence energy transfer and film morphology in breath figures and films.” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/24609.
MLA Handbook (7th Edition):
Nguyen, Vu Anh. “Blends of Polydioctylfluorene (PFO) with polymeric and monomeric energy acceptors: correlation of fluorescence energy transfer and film morphology in breath figures and films.” 2008. Web. 15 Jan 2021.
Vancouver:
Nguyen VA. Blends of Polydioctylfluorene (PFO) with polymeric and monomeric energy acceptors: correlation of fluorescence energy transfer and film morphology in breath figures and films. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/24609.
Council of Science Editors:
Nguyen VA. Blends of Polydioctylfluorene (PFO) with polymeric and monomeric energy acceptors: correlation of fluorescence energy transfer and film morphology in breath figures and films. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/24609
10.
Spears, Mark William.
Microgel-based coatings and their use as self-healing, dynamic substrates for bioapplications.
Degree: PhD, Chemistry and Biochemistry, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/53060
► Microgels are solvent swollen, cross-linked polymer macromolecules of micro or nanoscale dimensions. In this work, microgels are used as versatile building blocks in layer-by-layer assemblies…
(more)
▼ Microgels are solvent swollen, cross-linked polymer macromolecules of micro or nanoscale dimensions. In this work, microgels are used as versatile building blocks in layer-by-layer assemblies to form thin coatings. While conceptually simple materials, these microgel-based films actually possess extremely complex behavior as evidenced by two particular areas. First, microgel films have self-healing properties, allowing them to rapidly recover from damage in the presence of solvent. The healing step requires rearrangement of film components, demonstrating the dynamic and mobile nature of the films. Second, fibroblasts display complex behavior on microgel films arising from the properties of the coating. A chemical crosslinking treatment of the film affects the film network structure in a concentration-dependent manner. These network changes result in altered mechanical properties that are the primary controlling factor in determining cell behavior at the interface. These data suggest that fibroblasts are not solely controlled by the film elasticity, but rather by the viscoelasticity, and there is a viscoelastic range that results in maximal cell spreading.
Advisors/Committee Members: Lyon, Andrew (advisor), Fernández, Facundo M. (committee member), Dickson, Robert M. (committee member), Oyelere, Adegboyega K. (committee member), Fernandez-Nieves, Alberto (committee member).
Subjects/Keywords: Layer-by-layer; Microgels; Viscoelastic; Self-healing; Thin films
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APA (6th Edition):
Spears, M. W. (2014). Microgel-based coatings and their use as self-healing, dynamic substrates for bioapplications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53060
Chicago Manual of Style (16th Edition):
Spears, Mark William. “Microgel-based coatings and their use as self-healing, dynamic substrates for bioapplications.” 2014. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/53060.
MLA Handbook (7th Edition):
Spears, Mark William. “Microgel-based coatings and their use as self-healing, dynamic substrates for bioapplications.” 2014. Web. 15 Jan 2021.
Vancouver:
Spears MW. Microgel-based coatings and their use as self-healing, dynamic substrates for bioapplications. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/53060.
Council of Science Editors:
Spears MW. Microgel-based coatings and their use as self-healing, dynamic substrates for bioapplications. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53060
11.
Yu, George Yang.
Magnetic quartz crystal microbalance.
Degree: PhD, Electrical and Computer Engineering, 2008, Georgia Tech
URL: http://hdl.handle.net/1853/24615
► In this thesis, a new technique for using quartz crystal microbalance (QCM) in magnetic field was explored. This technique would take advantage of the sensitive…
(more)
▼ In this thesis, a new technique for using quartz crystal microbalance (QCM) in magnetic field was explored. This technique would take advantage of the sensitive nature of QCM to vibration changes. The idea is to perturb the QCM vibrations with magnetic materials on it by applying magnetic field. A new instrument called magnetic QCM (MQCM) was constructed to explore this technique.
The thesis contains three bodies of work. The first body describes the development of the MQCM instrument and the demonstration of the technique. The resonance frequency of a QCM with conducting polymer (polyaniline) suspension in poly(ethylene glycol) was observed to increase with increasing applied DC magnetic field. The change in population of free spins through doping with HCl vapor is reflected in increased frequency-field curve magnitude.
The second body of work describes the study of QCM proximity phenomenon discovered during the MQCM instrument development process. When an object approaches a vibrating QCM, the resonant frequency changes. This proximity effect is seen at the distance of 10 mm in air and becomes more pronounced as the distance decreases. This effect depends on the value of quality factor, conductivity of the object, and electrical connection of the object to the QCM electrodes. A simple modified Butterworth van-Dyke model is used to describe this effect. It must be recognized that this effect may lead to experimental artifacts in a variety of analytical QCM applications.
The third body of work describes an improved version of MQCM. The complex geometry such as particle suspension were simplified to alternating stack of ferromagnetic and diamagnetic layers. When magnetic field was applied, changes in the QCM admittance magnitude and phase curves were observed. A mass-equivalent stack of continuous consecutive layers of nickel and gold was also exposed to magnetic field but no changes were observed. Butterworth-van-Dyke model attributed the effect to internal shear friction loss among other losses is modulated by the magnetic field. Quantum effect was considered. However, after examining SEM surface images, the source of acoustic response to magnetic field is more likely from interfacial stresses.
Advisors/Committee Members: Janata, Jiri (Committee Chair), Hunt, William (Committee Co-Chair), Allen, Mark (Committee Member), Brand, Oliver (Committee Member), Ferguson, Ian (Committee Member), Lyon, Andrew (Committee Member).
Subjects/Keywords: Magnetic; Quartz crystal microbalance; Multi-layer; Gold nickel stack; Polyaniline; Particle suspension; Proximity effect; Magnetism; Magnetics; Thin films; Quartz crystal microbalances; Quartz crystals; Microbalances
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APA (6th Edition):
Yu, G. Y. (2008). Magnetic quartz crystal microbalance. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/24615
Chicago Manual of Style (16th Edition):
Yu, George Yang. “Magnetic quartz crystal microbalance.” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/24615.
MLA Handbook (7th Edition):
Yu, George Yang. “Magnetic quartz crystal microbalance.” 2008. Web. 15 Jan 2021.
Vancouver:
Yu GY. Magnetic quartz crystal microbalance. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/24615.
Council of Science Editors:
Yu GY. Magnetic quartz crystal microbalance. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/24615
12.
Mukherjee, Nimisha Gupta.
Analysis of the role of lipids in retrovirus transduction.
Degree: PhD, Biomedical Engineering, 2008, Georgia Tech
URL: http://hdl.handle.net/1853/31704
► The most common gene transfer vehicle used in gene therapy protocols are mammalian virus vectors. Specifically, retroviruses are one of the most common viral vectors…
(more)
▼ The most common gene transfer vehicle used in gene therapy protocols are mammalian virus vectors. Specifically, retroviruses are one of the most common viral vectors used since they are able to permanently integrate their transgene into the host cell genome, providing, in principal, to a long-term cure. The potential applications of gene therapies are vast, ranging from monogenic disorders such as cystic fibrosis to complex gene disorders such as cancer. However, the application of such therapies in clinical settings has been limited partially because of inefficient gene delivery of the therapeutic gene to diseased cells. Furthermore, safety concerns of accidently altering the genetic expression in healthy bystander cells or nearby tissue has increased the interest in creating targeted viral vectors which infect only the diseased cells without infecting others. Thus, the success of gene therapy will depend on identifying and understanding the parameters critical for virus entry into cells, including factors that facilitate virus absorption onto the cell surface, virus binding, and fusion. The objective of this thesis was to understand the role of lipids in binding and infection, and to investigate the use of lipid-based conjugates to alter the surface of virus particles.
Advisors/Committee Members: Le Doux, Joseph (Committee Chair), Bellamkonda, Ravi (Committee Member), Lyon, Andrew (Committee Member), Prausnitz, Mark (Committee Member), Spencer, Trent (Committee Member).
Subjects/Keywords: Gene therapy; Retrovirus; Targeting virus vectors; Lipids; Retroviruses; Retrovirus infections; Genetic transformation
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APA (6th Edition):
Mukherjee, N. G. (2008). Analysis of the role of lipids in retrovirus transduction. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/31704
Chicago Manual of Style (16th Edition):
Mukherjee, Nimisha Gupta. “Analysis of the role of lipids in retrovirus transduction.” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/31704.
MLA Handbook (7th Edition):
Mukherjee, Nimisha Gupta. “Analysis of the role of lipids in retrovirus transduction.” 2008. Web. 15 Jan 2021.
Vancouver:
Mukherjee NG. Analysis of the role of lipids in retrovirus transduction. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/31704.
Council of Science Editors:
Mukherjee NG. Analysis of the role of lipids in retrovirus transduction. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/31704
13.
Zhang, Yu.
Inverse opal scaffolds and photoacoustic microscopy for regenerative medicine.
Degree: PhD, Biomedical Engineering (Joint GT/Emory Department), 2013, Georgia Tech
URL: http://hdl.handle.net/1853/50231
► This research centers on the fabrication, characterization, and engineering of inverse opal scaffolds, a novel class of three-dimensional (3D) porous scaffolds made of biocompatible and…
(more)
▼ This research centers on the fabrication, characterization, and engineering of inverse
opal scaffolds, a novel class of three-dimensional (3D) porous scaffolds made of
biocompatible and biodegradable polymers, for applications in tissue engineering and
regenerative medicine. The unique features of an inverse opal scaffold include a highly
ordered array of pores, uniform and finely tunable pore sizes, high interconnectivity, and
great reproducibility.
The first part of this work focuses on the fabrication and functionalization of inverse
opal scaffolds based on poly(D,L-lactic-co-glycolic acid) (PLGA), a biodegradable
material approved by the U.S. Food and Drug Administration (FDA). The advantages of
the PLGA inverse opal scaffolds are also demonstrated by comparing with their
counterparts with spherical but non-uniform pores and poor interconnectivity.
The second part of this work shows two examples where the PLGA inverse opal
scaffolds were successfully used as a well-defined system to investigate the effect of pore
size of a 3D porous scaffold on the behavior of cell and tissue growth. Specifically, I
have demonstrated that i) the differentiation of progenitor cells in vitro was dependent on
the pore size of PLGA-based scaffolds and the behavior of the cells was determined by
the size of individual pores where the cells resided in, and ii) the neovascularization
process in vivo could be directly manipulated by controlling a combination of pore and
window sizes when they were applied to a mouse model.
The last part of this work deals with the novel application of photoacoustic
microscopy (PAM), a volumetric imaging modality recently developed, to tissue
engineering and regenerative medicine, in the context of non-invasive imaging and
quantification of cells and tissues grown in PLGA inverse opal scaffolds, both in vitro
and in vivo. Furthermore, the capability of PAM to monitor and quantitatively analyze
the degradation of the scaffolds themselves was also demonstrated.
Advisors/Committee Members: Xia, Younan (advisor), Wang, Lihong V. (committee member), Temenoff, Johnna S. (committee member), Barker, Thomas H. (committee member), Botchwey, Edward A. (committee member), Lyon, Andrew (committee member).
Subjects/Keywords: Tissue engineering; Regenerative medicine; Inverse opal scaffolds; Uniform; Poly(D,L-lactic-co-glycolic acid) (PLGA); Photoacoustic microscopy; Biomedical Imaging; Regeneration (Biology); Tissue scaffolds; Imaging systems in medicine; Biopolymers
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APA (6th Edition):
Zhang, Y. (2013). Inverse opal scaffolds and photoacoustic microscopy for regenerative medicine. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/50231
Chicago Manual of Style (16th Edition):
Zhang, Yu. “Inverse opal scaffolds and photoacoustic microscopy for regenerative medicine.” 2013. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/50231.
MLA Handbook (7th Edition):
Zhang, Yu. “Inverse opal scaffolds and photoacoustic microscopy for regenerative medicine.” 2013. Web. 15 Jan 2021.
Vancouver:
Zhang Y. Inverse opal scaffolds and photoacoustic microscopy for regenerative medicine. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/50231.
Council of Science Editors:
Zhang Y. Inverse opal scaffolds and photoacoustic microscopy for regenerative medicine. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/50231
Georgia Tech
14.
Cantor, Ryan Segler.
Sensing array for coherence analysis of modulated aquatic chemical plumes.
Degree: MS, Chemistry and Biochemistry, 2009, Georgia Tech
URL: http://hdl.handle.net/1853/28193
► An electrochemical sensor array can provide information about the spatial and temporal distribution of chemicals in liquid turbulent plumes. Planar laser induced fluorescence (PLIF) and…
(more)
▼ An electrochemical sensor array can provide information about the spatial and temporal distribution of chemicals in liquid turbulent plumes. Planar laser induced fluorescence (PLIF) and amperometric sensor arrays were used to record signals from modulated chemical plumes released into a recirculating aquatic flume. Coherence analysis was applied to extract the frequency components contained in the sensor response. Effects due to release distance, modulation frequency, and array orientation were investigated. This study has demonstrated that frequency encoded information can be extracted from a turbulent chemical plume using an array of amperometric sensors with optimized three-dimensional geometry and tuning.
Advisors/Committee Members: Janata, Jiri (Committee Chair), Lyon, Andrew (Committee Member), Weissburg, Marc (Committee Member).
Subjects/Keywords: Chemical plume tracking; Electrochemical sensor array; Chemical detectors; Plumes (Fluid dynamics); Eddies; Aquatic sciences; Coherence (Optics)
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APA (6th Edition):
Cantor, R. S. (2009). Sensing array for coherence analysis of modulated aquatic chemical plumes. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/28193
Chicago Manual of Style (16th Edition):
Cantor, Ryan Segler. “Sensing array for coherence analysis of modulated aquatic chemical plumes.” 2009. Masters Thesis, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/28193.
MLA Handbook (7th Edition):
Cantor, Ryan Segler. “Sensing array for coherence analysis of modulated aquatic chemical plumes.” 2009. Web. 15 Jan 2021.
Vancouver:
Cantor RS. Sensing array for coherence analysis of modulated aquatic chemical plumes. [Internet] [Masters thesis]. Georgia Tech; 2009. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/28193.
Council of Science Editors:
Cantor RS. Sensing array for coherence analysis of modulated aquatic chemical plumes. [Masters Thesis]. Georgia Tech; 2009. Available from: http://hdl.handle.net/1853/28193
Georgia Tech
15.
Agrawal, Amit.
Nanoparticle Probes for Ultrasensitive Biological Detection and Motor Protein Tracking inside Living Cells.
Degree: PhD, Biomedical Engineering, 2006, Georgia Tech
URL: http://hdl.handle.net/1853/19798
► Semiconductor quantum dots (QDs) have emerged as a new class of fluorescent probes and labeling agents for biological samples. QDs are bright, highly photostable and…
(more)
▼ Semiconductor quantum dots (QDs) have emerged as a new class of fluorescent probes and labeling agents for biological samples. QDs are bright, highly photostable and allow simultaneous excitation of multiple emissions. Owing to these properties, QDs hold exceptional promise in enabling intracellular biochemical studies and diagnosis with unprecedented sensitivity and accuracy. However, use of QD probes inside living cells remains a challenge due to difficulties in delivery of nanoparticles without causing aggregation and imaging single nanoparticles inside living cells. In this dissertation, a systematic approach to deliver, image and locate single QDs inside living cells is presented and the properties of molecular motor protein driven QD transport are studied. First, spectroscopic and imaging methods capable of differentiating single nanoparticles from the aggregates were developed. These technologies were validated by differentiating surface protein expression on viral particles and by enabling rapid counting of single biomolecules. Second, controlled delivery of single QDs into living cells is demonstrated. A surprising finding is that single QDs associate non-specifically with the dynein motor protein complex and are transported to the microtubule organizing center. Accurate localization and tracking of QDs inside cell cytoplasm revealed multiple dynein motor protein attachment resulting in increased velocity of the QDs. Further, spectrin molecule which is known to recruit dynein motor protein complex to phospholipid micelles was found to associate with the QDs. These results may serve as a benchmark for developing new QD surface coatings suitable for intracellular applications. Since, nanoparticles are similar in size to viral pathogens; better understanding of nanoparticle-cell interactions should also help engineer nanoparticle models to study virus-host cell interactions. (Contains AVI format multimedia files)
Advisors/Committee Members: Nie, Shuming (Committee Chair), Lyon, Andrew (Committee Member), Murthy, Niren (Committee Member), Petros, John (Committee Member), Zhu, Cheng (Committee Member).
Subjects/Keywords: Immunoassay; Single molecule detection; Live cell imaging; Quantum dots; Fluorescence; Motor protein; Viral trafficking; Dynein; Microtubule; Spectroscopy; Respiratory syncytial virus; Spectrin; Nucleic acid; Nanotechnology; Intracellular delivery; Color colocalization; Proteins; Magneto optical; Enrichment; Nanoparticles; Molecular probes; Quantum dots; Fluorescent probes; Cells
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APA (6th Edition):
Agrawal, A. (2006). Nanoparticle Probes for Ultrasensitive Biological Detection and Motor Protein Tracking inside Living Cells. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/19798
Chicago Manual of Style (16th Edition):
Agrawal, Amit. “Nanoparticle Probes for Ultrasensitive Biological Detection and Motor Protein Tracking inside Living Cells.” 2006. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/19798.
MLA Handbook (7th Edition):
Agrawal, Amit. “Nanoparticle Probes for Ultrasensitive Biological Detection and Motor Protein Tracking inside Living Cells.” 2006. Web. 15 Jan 2021.
Vancouver:
Agrawal A. Nanoparticle Probes for Ultrasensitive Biological Detection and Motor Protein Tracking inside Living Cells. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/19798.
Council of Science Editors:
Agrawal A. Nanoparticle Probes for Ultrasensitive Biological Detection and Motor Protein Tracking inside Living Cells. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/19798
Georgia Tech
16.
Jain, Swapan Satyen.
Nucleic Acid Assembly Using Small Molecule Interactions.
Degree: PhD, Chemistry and Biochemistry, 2006, Georgia Tech
URL: http://hdl.handle.net/1853/11596
► Lifes origin is, in many ways, coupled to understanding the evolution of nucleic acids. In contemporary life, proteins and nucleic acids are intricately dependent upon…
(more)
▼ Lifes origin is, in many ways, coupled to understanding the evolution of nucleic acids. In contemporary life, proteins and nucleic acids are intricately dependent upon each other for a host of functions including, but not limited to, replication and chemical ligation. Protein enzymes are necessary for the synthesis of DNA and RNA, while nucleic acids are necessary for both the coding and synthesis of proteins. According to the RNA World hypothesis, early life used nucleic acids for both information storage and chemical catalysis before the emergence of protein enzymes. However, it still remains a mystery how nucleic acids were able to assemble and replicate before the advent of protein enzymes. We have utilized the ability of small molecule intercalation to assemble nucleic acids into stable secondary structures. Our motivation in this pursuit comes from the recently proposed Molecular Midwife hypothesis where small molecules may have acted as nanoscale structural scaffolds upon which the nucleic acid bases were able to stack into stable structures and undergo assembly into polymers. We have also found that the kinetics and thermodynamics of small molecule-mediated assembly and secondary structure formation are strongly dependent upon oligonucleotide length. Small molecules bind to nucleic acids by multiple modes of binding and this phenomenon must be properly understood in order to achieve robust and versatile assembly of nucleic acid structures.
Advisors/Committee Members: Hud, Nicholas (Committee Chair), Doyle, Donald (Committee Member), Lyon, Andrew (Committee Member), Williams, Loren (Committee Member), Wilson, David (Committee Member).
Subjects/Keywords: Proflavine; Assembly; Coralyne; Intercalation; Molecular midwife hypothesis; Nucleic acids; Ligation
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APA (6th Edition):
Jain, S. S. (2006). Nucleic Acid Assembly Using Small Molecule Interactions. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/11596
Chicago Manual of Style (16th Edition):
Jain, Swapan Satyen. “Nucleic Acid Assembly Using Small Molecule Interactions.” 2006. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/11596.
MLA Handbook (7th Edition):
Jain, Swapan Satyen. “Nucleic Acid Assembly Using Small Molecule Interactions.” 2006. Web. 15 Jan 2021.
Vancouver:
Jain SS. Nucleic Acid Assembly Using Small Molecule Interactions. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/11596.
Council of Science Editors:
Jain SS. Nucleic Acid Assembly Using Small Molecule Interactions. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/11596
Georgia Tech
17.
Chi, San-Hui.
Third-order nonlinear optical properties of conjugated polymers and blends.
Degree: PhD, Chemistry and Biochemistry, 2009, Georgia Tech
URL: http://hdl.handle.net/1853/31664
► This thesis is concerned with the material processing, photophysical and third-order nonlinear optical responses, and applications of a set of conjugated polymers in the telecommunication…
(more)
▼ This thesis is concerned with the material processing, photophysical and third-order nonlinear optical responses, and applications of a set of conjugated polymers in the telecommunication regions.
Polyacetylene-based third-order nonlinear optical materials were chosen as candidates for all-optical signal and image processing. Substituted polyacetylenes were obtained using ring-opening metathesis polymerization of mono-substituted cyclooctatetraenes. Polymerization and processing conditions have been developed to generate thick, large-area films possessing large third-order nonlinearities in the telecommunication bands. The good optical quality of a 200 μm thick substituted polyacetylene film allowed for image correlation via off-resonant degenerated four-wave mixing with improved diffraction efficiency.
Poly(2-methoxy-5-(2-ethyl-hexyloxy)-(phenylene vinylene)) (MEH-PPV) and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) composites showed strong nonlinear absorption and potential as optical limiters in the region of 700-900 nm. High optical quality, thick film of MEH-PPV:PCBM with the plasticizer dioctylphthalate (DOP) were made. Optical limiting of femtosecond and nanosecond pulses in the near infrared on these composites showed strong power suppression over a broad temporal regime. Femtosecond and nanosecond transient studies on the same thick MEH-PPV:PCBM:DOP composite films and the experimental results showed evidence for the photogeneration of radical ions as being responsible for the enhanced nonlinear absorption and strong optical suppression in the near infrared.
Dithienopyrrole-based donor-acceptor copolymers with narrow bandgap showed strong nonlinear absorption and potential as optical limiters in the telecommunication wavelengths. Molecular engineering was applied to manipulate the spectral overlap of two-photon absorption and subsequent nonlinear absorptions. Femtosecond transient spectroscopy showed near infrared transient absorption and 22 - 61% yields of photogenerated charge-transfer species depending on donor-acceptor coupling strength. Torsional fluctuations of the backbone structure potentially affected the excited state behavior. Evidence suggests that ultrafast relaxation occurs to ground state and to long-lived charge-transfer state from the initially excited state. The dispersion of nonlinear absorption measured using the Z-scan method revealed large two-photon absorption cross sections of these polymers in the telecommunication region. Large suppression of nanosecond pulses at 1064 nm was achieved.
Advisors/Committee Members: Perry, Joseph (Committee Chair), Bunz, Uwe (Committee Member), Lyon, Andrew (Committee Member), Marder, Seth (Committee Member), Trebino, Rick (Committee Member).
Subjects/Keywords: Polyphenylenevinylene; Dithenopyrrole; Charge transfer; Photo-induced charge transfer; Optical limiting; Conjugated polymers; Nonlinear optics; Nonlinear optical material; Image recognition; Polyacetylene; Photovoltaic power generation; Polymers Optical properties
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APA (6th Edition):
Chi, S. (2009). Third-order nonlinear optical properties of conjugated polymers and blends. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/31664
Chicago Manual of Style (16th Edition):
Chi, San-Hui. “Third-order nonlinear optical properties of conjugated polymers and blends.” 2009. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/31664.
MLA Handbook (7th Edition):
Chi, San-Hui. “Third-order nonlinear optical properties of conjugated polymers and blends.” 2009. Web. 15 Jan 2021.
Vancouver:
Chi S. Third-order nonlinear optical properties of conjugated polymers and blends. [Internet] [Doctoral dissertation]. Georgia Tech; 2009. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/31664.
Council of Science Editors:
Chi S. Third-order nonlinear optical properties of conjugated polymers and blends. [Doctoral Dissertation]. Georgia Tech; 2009. Available from: http://hdl.handle.net/1853/31664
Georgia Tech
18.
Bridges, Amanda Walls.
Host responses to microgel-based biomaterial interfaces.
Degree: PhD, Biomedical Engineering, 2008, Georgia Tech
URL: http://hdl.handle.net/1853/31701
► Although medical devices and biomaterial implants are used clinically in a variety of applications, the process of implanting them damages local tissue and initiates a…
(more)
▼ Although medical devices and biomaterial implants are used clinically in a variety of applications, the process of implanting them damages local tissue and initiates a localized non-specific inflammatory response that is detrimental to device performance. Extensive research efforts have focused on developing material surface treatments and systems to deliver anti-inflammatory agents to abrogate such biomaterial-mediated inflammation, yet long-term use of these traditional materials in vivo is limited due to continued inflammation and fibrous encapsulation. This work aims to address these limitations by developing a versatile implant coating with non-fouling properties using a system based on hydrogel microparticles (i.e. microgels). The overall objective of this project was to evaluate host responses to these microgel coatings.
Microgel particles were synthesized from poly(N-isopropyl acrylamide) cross-linked with poly(ethylene glycol)-diacrylate and were successfully deposited onto polymeric substrates using a simple and reproducible spin coating technique. We determined that microgel-coated samples adsorbed significantly lower levels of human fibrinogen than controls. Further characterization using an in vitro culture system demonstrated that microgel coatings significantly reduced the adhesion and spreading of murine macrophages and primary human blood-derived monocytes compared to controls.
Materials were then evaluated for early cellular responses following implantation in the intraperitoneal cavity of mice to model acute inflammation. Analyses of explanted biomaterials using immunofluorescence staining techniques revealed that microgel-coated samples significantly reduced the density of surface-adherent cells. Additional analysis using flow cytometry revealed that microgel-coated samples exhibited significantly lower levels of pro-inflammatory cytokines in adherent leukocytes compared to controls, indicating that these coatings modulate cellular pro-inflammatory activities.
Finally, we implanted samples subcutaneously in rats to determine the efficacy of microgel coatings at longer time points using an established model of chronic inflammation. Explants were processed histologically and stained for various markers. Importantly, staining demonstrated that the microgel coatings significantly reduced fibrous capsule thickness, the capsules appeared less compact and structurally ordered than controls, and also contained significantly fewer cells. Collectively, these results demonstrate that microgel particles can be applied as polymeric coatings to modulate inflammation and achieve more desirable host responses in vivo, with the potential to extend implant lifetime.
Advisors/Committee Members: Garcia, Andres (Committee Chair), Babensee, Julia (Committee Member), Bellamkonda, Ravi (Committee Member), Lyon, Andrew (Committee Member), Temenoff, Johnna (Committee Member).
Subjects/Keywords: Microgel; Hydrogel; Coating; Macrophage; Foreign body response; Inflammation; Biomaterials; Polymer; Biomedical materials; Colloids; Colloids in medicine; Macrophages; Leucocytes; Implants, Artificial
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APA (6th Edition):
Bridges, A. W. (2008). Host responses to microgel-based biomaterial interfaces. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/31701
Chicago Manual of Style (16th Edition):
Bridges, Amanda Walls. “Host responses to microgel-based biomaterial interfaces.” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/31701.
MLA Handbook (7th Edition):
Bridges, Amanda Walls. “Host responses to microgel-based biomaterial interfaces.” 2008. Web. 15 Jan 2021.
Vancouver:
Bridges AW. Host responses to microgel-based biomaterial interfaces. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/31701.
Council of Science Editors:
Bridges AW. Host responses to microgel-based biomaterial interfaces. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/31701
Georgia Tech
19.
Hicks, Jason Christopher.
Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: synthesis, characterization and application.
Degree: PhD, Chemical Engineering, 2007, Georgia Tech
URL: http://hdl.handle.net/1853/26583
► The major goals of this thesis were to: (1) create a site-isolated aminosilica material with higher amine loadings than previously reported isolation methods, (2) use…
(more)
▼ The major goals of this thesis were to: (1) create a site-isolated aminosilica material with higher amine loadings than previously reported isolation methods, (2) use spectroscopic, reactivity, and catalytic (olefin polymerization precatalysts) probes to determine isolation of amine groups on these organic/inorganic hybrid materials, (3) synthesize an organic/inorganic hybrid material capable of activating Group 4 olefin polymerization precatalysts, and (4) synthesize a high amine loaded organic/inorganic hybrid material capable of reversibly capturing CO2 in a simulated flue gas stream.
The underlying motivation of this research involved the synthesis and design of novel amine and sulfonic acid materials. Traditional routes to synthesize aminosilicas have led to the formation of a high loading of multiple types of amine sites on the silica surface. Part of this research involved the creation of a new aminosilica material via a protection/deprotection method designed to prevent multiple sites, while maintaining a relatively high loading. As a characterization technique, fluorescence spectroscopy of pyrene-based fluorophores loaded on traditional aminosilicas and site-isolated aminosilicas was used to probe the degree of site-isolation obtained with these methods. Also, this protection/deprotection method was compared to other reported isolation techniques with heterogeneous Group 4 constrained-geometry inspired catalysts (CGCs). It was determined that the degree of separation of the amine sites could be controlled with protection/deprotection methods. Furthermore, an increase in the reactivity of the amines and the catalytic activity of CGCs built off of the amines was determined for aminosilicas synthesized by a protection/deprotection method. The second part of this work involved developing organic/inorganic hybrid materials as heterogeneous Brønsted acidic cocatalysts for activation of olefin polymerization precatalysts. This was the first reported organic/inorganic hybrid sulfonic acid functionalized silica material capable of activating metallocenes for the polymerization of ethylene when small amounts of an alkylaluminum was added. Lastly, an organic/inorganic hybrid hyperbranched aminosilica material capable of capturing carbon dioxide from flue gas streams was synthesized. This material was determined to capture CO2 with capacities higher than currently reported aminosilica adsorbents.
Advisors/Committee Members: Jones, Christopher (Committee Chair), Koros, William (Committee Member), Lyon, Andrew (Committee Member), Nair, Sankar (Committee Member), Weck, Marcus (Committee Member).
Subjects/Keywords: Mesoporous; Silica; Aminosilica; Olefin polymerization; Amine separation; Tethering; Amines; Silica; Composite materials; Alkenes; Flue gases; Sulfonic acids; Metallocenes; Polymerization
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APA (6th Edition):
Hicks, J. C. (2007). Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: synthesis, characterization and application. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/26583
Chicago Manual of Style (16th Edition):
Hicks, Jason Christopher. “Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: synthesis, characterization and application.” 2007. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/26583.
MLA Handbook (7th Edition):
Hicks, Jason Christopher. “Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: synthesis, characterization and application.” 2007. Web. 15 Jan 2021.
Vancouver:
Hicks JC. Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: synthesis, characterization and application. [Internet] [Doctoral dissertation]. Georgia Tech; 2007. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/26583.
Council of Science Editors:
Hicks JC. Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: synthesis, characterization and application. [Doctoral Dissertation]. Georgia Tech; 2007. Available from: http://hdl.handle.net/1853/26583
Georgia Tech
20.
Karlowatz, Manfred.
Part I. From the Lab to the Field - Recent Developments in Polymer Coated ATR Sensing for the Determination of Volatile Organic Compounds ; Part II. From the Field to the Lab - Investigating IR Signatures for Remote Sensing Applications.
Degree: PhD, Chemistry and Biochemistry, 2004, Georgia Tech
URL: http://hdl.handle.net/1853/5005
► Part I: Successful transition of polymer coated, ATR-FTIR sensor devices from a laboratory environment to real world field applications for detecting and quantifying VOCs in…
(more)
▼ Part I:
Successful transition of polymer coated, ATR-FTIR sensor devices from a laboratory environment to real world field applications for detecting and quantifying VOCs in water is shown. Simultaneous, quantitative detection of BTX mixtures in water during enrichment into polymer coated ZnSe ATR elements has been performed. The obtained results showed accurate detection and quantification to the low ppb concentration region. Fiber-optic evanescent field measurement campaigns have been conducted at simulated field conditions during which concentration gradients of various VOCs in the mg/L range have been monitored successfully. The first test of an ATR based, polymer coated sensor system under real world field conditions, the chlorobenzene concentration in groundwater at mg/L levels was determined. An interesting aspect of these measurements was the experimental proof for the dependence of analyte extraction dynamics on the flow conditions of the sample matrix surrounding the extractive polymer membrane. The obtained results demonstrate that MIR evanescent field sensors are suitable for in-situ analysis at real world field conditions for environmental monitoring applications.
PART II:
Recently, measurements of disturbed soils have shown different spectral contrast in comparison to undisturbed soils. In this work first measurements at controlled laboratory conditions have been performed to investigate individual minerals of the soil matrix and their spectral characteristics under various environmental conditions. ATR spectroscopy has been applied to investigate multi-disperse quartz sand and mono-disperse soda lime glass spheres samples. For the investigation of spectral differences between pristine and disturbed quartz sand, a wetting/drying procedure with subsequent sample aerating has been developed. In addition to established differences in spectral contrast of disturbed and undisturbed soil, a strong spectral shift of absorption features was observed. When probed with s- or p-polarized light, both samples showed strong LO-TO mode splitting. The studies also reveal that the main reason for spectral differences of pristine and disturbed soils is caused by water facilitated changes of the particle size distribution in the probed volume. The presented results advance the variety of spectral characteristics useful for the detection of disturbed soils (i.e. possible landmine sites) with MIR imaging systems.
Advisors/Committee Members: Mizaikoff, Boris (Committee Chair), Janata, Jiri (Committee Member), Loeffler, Frank (Committee Member), Lyon, Andrew (Committee Member), Orlando, Thomas (Committee Member), Weck, Marcus (Committee Member).
Subjects/Keywords: Groundwater monitoring; Chlorobenzene; Volatile organic compounds (VOCs); Quartz; Infrared spectroscopy; Mid-infrared chemical sensors; Attenuated total reflection (ATR) spectroscopy; Remote sensing
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APA (6th Edition):
Karlowatz, M. (2004). Part I. From the Lab to the Field - Recent Developments in Polymer Coated ATR Sensing for the Determination of Volatile Organic Compounds ; Part II. From the Field to the Lab - Investigating IR Signatures for Remote Sensing Applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/5005
Chicago Manual of Style (16th Edition):
Karlowatz, Manfred. “Part I. From the Lab to the Field - Recent Developments in Polymer Coated ATR Sensing for the Determination of Volatile Organic Compounds ; Part II. From the Field to the Lab - Investigating IR Signatures for Remote Sensing Applications.” 2004. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/5005.
MLA Handbook (7th Edition):
Karlowatz, Manfred. “Part I. From the Lab to the Field - Recent Developments in Polymer Coated ATR Sensing for the Determination of Volatile Organic Compounds ; Part II. From the Field to the Lab - Investigating IR Signatures for Remote Sensing Applications.” 2004. Web. 15 Jan 2021.
Vancouver:
Karlowatz M. Part I. From the Lab to the Field - Recent Developments in Polymer Coated ATR Sensing for the Determination of Volatile Organic Compounds ; Part II. From the Field to the Lab - Investigating IR Signatures for Remote Sensing Applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/5005.
Council of Science Editors:
Karlowatz M. Part I. From the Lab to the Field - Recent Developments in Polymer Coated ATR Sensing for the Determination of Volatile Organic Compounds ; Part II. From the Field to the Lab - Investigating IR Signatures for Remote Sensing Applications. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/5005
Georgia Tech
21.
Hathcock, David Jackson.
Dynamic and Catalytic Properties of Some Metallic Nanoparticles.
Degree: PhD, Chemistry and Biochemistry, 2004, Georgia Tech
URL: http://hdl.handle.net/1853/5134
► Using a variety of techniques including femtosecond transient absorption spectroscopy, optical absorption, atomic force microscopy, the hot electron cooling dynamics of lithographically prepared gold nanoarrays,…
(more)
▼ Using a variety of techniques including femtosecond transient absorption spectroscopy, optical absorption, atomic force microscopy, the hot electron cooling dynamics of lithographically prepared gold nanoarrays, the effect of the surrounding environment, and the phonon oscillations of gold and silver nano-arrays were investigated. The cooling dynamics of gold nanoarrays on a glass substrate were found to be different from those of either colloidal nanodots in colloidal solution or films on glass substrate. The electron-phonon component of the electronic relaxation in the arrays was found to be longer than that in the dots or the films. The spatially isolated nanoarray particles experience a significantly different environment than the gold nanodots in solution, thus the long phonon-phonon component resulting from the coupling of particles to the medium, is not observed. The catalytic effectiveness of platinum nanoparticles for the hydrogenation of propene was investigated. The system with platinum particles was found to have a slightly lower activation energy than other systems in the literature. The effect of encapsulating the platinum particles in alumina was also investigated and it was found that the activation energy for the reaction was even lower. The effect of adding platinum, palladium, and rhodium particles to the proton exchange membrane of polymer electrolyte fuel cells, on the output power of the cells was also investigated. The effects of pH and precursor salt concentration, and particle composition were also investigated.
Advisors/Committee Members: El-Sayed, Mostafa A. (Committee Chair), Lyon, Andrew (Committee Member), Wang, Z.L. (Committee Member), Whetten, Robert (Committee Member), Zhang, John (Committee Member).
Subjects/Keywords: Gold nanoparticles
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APA (6th Edition):
Hathcock, D. J. (2004). Dynamic and Catalytic Properties of Some Metallic Nanoparticles. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/5134
Chicago Manual of Style (16th Edition):
Hathcock, David Jackson. “Dynamic and Catalytic Properties of Some Metallic Nanoparticles.” 2004. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/5134.
MLA Handbook (7th Edition):
Hathcock, David Jackson. “Dynamic and Catalytic Properties of Some Metallic Nanoparticles.” 2004. Web. 15 Jan 2021.
Vancouver:
Hathcock DJ. Dynamic and Catalytic Properties of Some Metallic Nanoparticles. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/5134.
Council of Science Editors:
Hathcock DJ. Dynamic and Catalytic Properties of Some Metallic Nanoparticles. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/5134
Georgia Tech
22.
Qi, Genggeng.
Unconventional radical miniemulsion polymerization.
Degree: PhD, Chemical Engineering, 2008, Georgia Tech
URL: http://hdl.handle.net/1853/26547
► Conventional free-radical miniemulsion polymerization has been well studied since early 1970s. Conventional free-radical miniemulsion polymerizations have inherent limitations associated with uncontrolled free-radical polymerization mechanism. The…
(more)
▼ Conventional free-radical miniemulsion polymerization has been well studied since early 1970s. Conventional free-radical miniemulsion polymerizations have inherent limitations associated with uncontrolled free-radical polymerization mechanism. The goal of this work is to develop a variety of unconventional miniemulsion polymerization techniques by applying new polymerization techniques (typically in solution or bulk) to miniemulsion systems to overcome their inherent limitations and extend the application of free-radical miniemulsion polymerization.
This work focused on the exploration of kinetic and mechanistic aspects of unconventional miniemulsion polymerizations. First, enzyme initiated free-radical miniemulsion polymerization, in contrast with those conventional chemical initiated miniemulsion polymerization, is demonstrated for the first time as an answer to the challenges associated with using the hydrophobic of vinyl monomers in aqueous enzymatic reactions. A procedure for enzyme initiated free-radical miniemulsion polymerization was formulated and stable poly(styrene) latexes were successfully synthesized. The kinetics of enzyme initiated free-radical miniemulsion polymerization and the effect of reaction conditions on the polymerization was elucidated. Second, RAFT miniemulsion polymerization of hydrophobic monomers was performed in CSTR trains and the transient states, previously identified by others in our group, were elucidated. Next, RAFT miniemulsion polymerization of a partially water soluble monomer was studied. RAFT miniemulsion polymerizations of gamma-methyl-alpha-methylene-gamma-butyrolactone, a partially water soluble lactone monomer derived from renewable sources, was successfully formulated. Homogeneous nucleation was found to play an important role in the free-radical "miniemulsion" homopolymerization of MeMBL. By using styrene as a comonomer, the RAFT miniemulsion polymerizations of MeMBL and styrene were well controlled and narrowly distributed copolymers of MeMBL/styrene were produced. Following the study of the partially water monomer, RAFT inverse miniemulsion polymerization was proposed for the polymerization of hydrophilic monomers. The kinetics of RAFT inverse miniemulsion polymerization of acrylamide exhibited the typical behavior of controlled polymerizations up to high conversions. The effects of reaction parameters on the polymerization rate and particle size were investigated. The dominant locus of radical generation for particle nucleation and the fate of desorbed monomeric radicals in inverse miniemulsion polymerizations were evaluated. Finally in this work, conclusions and implications are presented and ideas for future work are suggested.
Advisors/Committee Members: Jones, Christopher W. (Committee Chair), Schork, F. Joseph (Committee Chair), Koros, William J. (Committee Member), Lyon, Andrew (Committee Member), Nenes, Athanasios (Committee Member).
Subjects/Keywords: Miniemulsion polymerization; Controlled polymerization; Inverse miniemulsion; Enzymatic polymerization; Biomass; Emulsion polymerization
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APA ·
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MLA ·
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CSE |
Export
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APA (6th Edition):
Qi, G. (2008). Unconventional radical miniemulsion polymerization. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/26547
Chicago Manual of Style (16th Edition):
Qi, Genggeng. “Unconventional radical miniemulsion polymerization.” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/26547.
MLA Handbook (7th Edition):
Qi, Genggeng. “Unconventional radical miniemulsion polymerization.” 2008. Web. 15 Jan 2021.
Vancouver:
Qi G. Unconventional radical miniemulsion polymerization. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/26547.
Council of Science Editors:
Qi G. Unconventional radical miniemulsion polymerization. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/26547
Georgia Tech
23.
Jarvholm, Erik Jonas.
Mechanisms and Development of Etch Resistance for Highly Aromatic Monomolecular Etch Masks - Towards Molecular Lithography.
Degree: PhD, Chemistry and Biochemistry, 2007, Georgia Tech
URL: http://hdl.handle.net/1853/14640
► The road map of the semiconductor industry has followed Moores Law over the past few decades. According to Moores Law the number of transistors in…
(more)
▼ The road map of the semiconductor industry has followed Moores Law over the past few decades. According to Moores Law the number of transistors in an integrated circuit (IC) will double for a minimum component cost every two years. The features made in an IC are produced by photolithography. Industry is now producing devices at the 65 nm node, however, for every deceasing node size, both the materials and processes used are not only difficult but also expensive to develop. Ultimately, the feature size obtainable via photolithography is dependent on the wavelength used in the process. The limitations of photolithography will eventually make Moores Law unsustainable. Therefore, new methodologies of creating features in the semiconductor substrate are desired.
Here we present a new way to make patterns in silicon (Si) and silicon dioxide (SiO2), molecular lithography. Individual molecules and polymers, in a monolayer, serves directly as the etch mask; eliminating the photolighographic size limitation of light at a specific wavelength. The Ohnishi- and Ring parameter suggests that cyclic carbon rich molecules have a high resistance towards the plasma process, used to create the features in the substrate. Therefore highly aromatic molecules were investigated as candidates for molecular lithography.
A monolayer of poly cyclic hydrocarbons, fullerene containing polymer, and fullerene molecules were created using the versatile photochemistry of benzophenone as the linker between the substrate and the material. First, a chlorosilane benzophenone derivative was attached to the Si/SiO2 surface. A thin film of the desired material is then created on top of the silane benzophenone layer. Irradiation at ~350 nm excites the benzophenone and reacts with neighboring alkyl chains. After covalent attachment the non-bonded molecules are extracted from the surface using a Soxhlet apparatus. Self-assembly, molecular weight, and wetting properties of the material dictates the features shape and size. These features are then serving as an etchmask in a fluorine plasma. The organic etch resist is then removed either in an oxygen plasma or in a piranha solution. AFM analysis revealed that 3 to 4 nm wide defined structures were obtained using C96 as the etch mask. This is about ten times smaller then industry standards. Also a depth profile of 50 nm, which is the minimum feature depth used in industry, was created using a fullerene containing polymer as the etch mask. Directionality and control over the shape and sizes of the features are naturally critical for implementing this technology in device fabrication. Therefore, alignment of the materials used has also been examined.
Monolayers of highly stable molecules has successfully been used as etch masks. Further research and development could implement molecular lithography in device fabrication. Self-assembly among other forces would dictate which materials could be used successfully as a molecular resist.
Advisors/Committee Members: Tolbert, Laren (Committee Chair), Bottomley, Lawrence (Committee Member), Henderson, Clifford (Committee Member), Hess, Dennis (Committee Member), Lyon, Andrew (Committee Member), Srinivasarao, Mohan (Committee Member).
Subjects/Keywords: Molecular lithography; Etch resistance; Aromatic; Monolayer; Nanostructures; Etch masks; Monomolecular films; Semiconductors Etching; Self-assembly (Chemistry)
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APA (6th Edition):
Jarvholm, E. J. (2007). Mechanisms and Development of Etch Resistance for Highly Aromatic Monomolecular Etch Masks - Towards Molecular Lithography. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/14640
Chicago Manual of Style (16th Edition):
Jarvholm, Erik Jonas. “Mechanisms and Development of Etch Resistance for Highly Aromatic Monomolecular Etch Masks - Towards Molecular Lithography.” 2007. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/14640.
MLA Handbook (7th Edition):
Jarvholm, Erik Jonas. “Mechanisms and Development of Etch Resistance for Highly Aromatic Monomolecular Etch Masks - Towards Molecular Lithography.” 2007. Web. 15 Jan 2021.
Vancouver:
Jarvholm EJ. Mechanisms and Development of Etch Resistance for Highly Aromatic Monomolecular Etch Masks - Towards Molecular Lithography. [Internet] [Doctoral dissertation]. Georgia Tech; 2007. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/14640.
Council of Science Editors:
Jarvholm EJ. Mechanisms and Development of Etch Resistance for Highly Aromatic Monomolecular Etch Masks - Towards Molecular Lithography. [Doctoral Dissertation]. Georgia Tech; 2007. Available from: http://hdl.handle.net/1853/14640
Georgia Tech
24.
Chen, Hang.
Modulation Effects on Organic Electronics.
Degree: PhD, Chemistry and Biochemistry, 2005, Georgia Tech
URL: http://hdl.handle.net/1853/7594
► A high aspect ratio epoxy mask has been built with Taiyo PSR4000BN on chemical sensing array chip. Thickness up to 200 and61549;m and aspect ratio…
(more)
▼ A high aspect ratio epoxy mask has been built with Taiyo PSR4000BN on chemical sensing array chip. Thickness up to 200 and61549;m and aspect ratio up to 16:1 have been achieved with this material. It is demonstrated that this material satisfies the mechanical and chemical requirements. A three-electrode system has been designed and built for electrochemistry in micro-cell on chip. Tests with poly(phenylenesulfide-phenyleneamine) (PPSA) demonstrates that it is possible to precisely tune the properties (Work function and resistance) of conducting polymer that has been cast on chip surface.
A new test platform GT03 has been fabricated and used to characterize the chemical effects on organic electronics. It is demonstrated that the chemical species in ambient environment can affect organic electronics properties on bulk, interface and electric contact. The contact resistance in organic field-effect transistors (OFETs) has been characterized with modified interdigitated structure (IDS). It is demonstrated that drain and source contact resistances can be calculated separately with modified four-point-probe measurements, and contact resistance and material bulk resistance are actually modulated by the gate electric field. Furthermore, the influence from oxygen doping in poly(3-hexylthiophene) (P3HT) based OFETs has been investigated. A new model of oxygen doping has been suggested and it is demonstrated that oxygen doping can affect all the resistance components in P3HT OFETs.
Advisors/Committee Members: Janata, Jiri (Committee Chair), Josowicz, Mira (Committee Member), Kippelen, Bernard (Committee Member), Lyon, Andrew (Committee Member), Zhang, John Z. (Committee Member).
Subjects/Keywords: Contact resistance; Field modulation; Organic field-effect transistor; Chemical effects; Organic electronics
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APA (6th Edition):
Chen, H. (2005). Modulation Effects on Organic Electronics. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/7594
Chicago Manual of Style (16th Edition):
Chen, Hang. “Modulation Effects on Organic Electronics.” 2005. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/7594.
MLA Handbook (7th Edition):
Chen, Hang. “Modulation Effects on Organic Electronics.” 2005. Web. 15 Jan 2021.
Vancouver:
Chen H. Modulation Effects on Organic Electronics. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/7594.
Council of Science Editors:
Chen H. Modulation Effects on Organic Electronics. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/7594
Georgia Tech
25.
Chen, Haiyan.
Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption.
Degree: PhD, Chemistry and Biochemistry, 2006, Georgia Tech
URL: http://hdl.handle.net/1853/10427
► Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption Haiyan Chen 133 Pages Directed by Professor Thomas M. Orlando Polycrystalline gadolinia-doped…
(more)
▼ Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption
Haiyan Chen
133 Pages
Directed by Professor Thomas M. Orlando
Polycrystalline gadolinia-doped ceria (GDC) has been widely investigated as a promising low temperature solid oxide fuel cell (SOFC) electrolyte and as part of composite electrodes. In this thesis, electron stimulated desorption (ESD) has been used to probe the defect related electronic properties of GDC surfaces and the interactions of water and molecular oxygen with these surfaces.
In particular, the electron irradiation induced surface charging of GDC has been found to be dependent on the incident electron energy: negative at lower energy and positive at higher energy. Trapping of electrons and holes by the gadolinium aggregated, oxygen vacancy rich grain boundaries has been considered as the origin of surface charging. Depending on the sample treatment, there can be various defects, hydroxyl groups, chemically adsorbed water molecules, or water dimers on GDC surfaces. Water and molecular oxygen interact primarily with defect sites.
Systematic investigations of electron stimulated O+ desorption have yielded activation energies relevant to oxygen vacancy production on ceria surfaces, and to surface positive charge dissipation related to ionic conduction of GDC. Highly efficient electron stimulated O+ desorption from GDC surfaces has been attributed to the lowered charge density on oxygen ions coordinated with oxygen vacancy clusters and thus may be used as a probe for surface defect types.
Electron stimulated desorption of O2+ from GDC surfaces during molecular oxygen adsorption has shown the ability of ESD to detect chemically adsorbed O2. The velocity distributions of O2+ can be used to probe intermediate adsorption species such as O2, as well as the positive charge of the surface.
Overall, this thesis has demonstrated that ESD can provide important information on the kinetics and dynamics of surface charging, charge transport, adsorption and reactions occurring at defective insulating metal oxides materials. The abilities to probe the defects and their roles in surface processes make ESD a valuable technique for surface chemistry and catalysis studies.
Advisors/Committee Members: Orlando, Thomas (Committee Chair), Liu, Meilin (Committee Co-Chair), First, Phillip (Committee Member), Janata, Jiri (Committee Member), Lyon, Andrew (Committee Member), Whetten, Robert (Committee Member).
Subjects/Keywords: Oxygen vacancy; Surface charging
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APA ·
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MLA ·
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Export
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APA (6th Edition):
Chen, H. (2006). Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/10427
Chicago Manual of Style (16th Edition):
Chen, Haiyan. “Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption.” 2006. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/10427.
MLA Handbook (7th Edition):
Chen, Haiyan. “Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption.” 2006. Web. 15 Jan 2021.
Vancouver:
Chen H. Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/10427.
Council of Science Editors:
Chen H. Probing Defects and Electronic Processes on Gadolinia-doped Ceria Surfaces Using Electron Stimulated Desorption. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/10427
Georgia Tech
26.
Zheng, Jie.
Fluorescent noble metal nanoclusters.
Degree: PhD, Chemistry and Biochemistry, 2005, Georgia Tech
URL: http://hdl.handle.net/1853/10574
► Water-soluble fluorescent metallic clusters at sizes comparable to the Fermi wavelength of an electron (~0.5 nm for gold and silver) were created and their photophysical…
(more)
▼ Water-soluble fluorescent metallic clusters at sizes comparable to the Fermi wavelength of an electron (~0.5 nm for gold and silver) were created and their photophysical properties were investigated at the bulk and single molecule levels. We employed biocompatible dendrimer and peptide to prepare a series of strong fluorescent gold and silver clusters with chemical or photo reduction methods. Facilitated by the well-defined dendrimer size, electrospray ionization mass spectrometry indicates that the fluorescent silver nanocluster size ranges from 2 to 8 Ag atoms. The correlation of emission energy with the number of atoms, N, in each gold nanocluster is quantitatively fit for the smallest nanoclusters with no adjustable parameters by the simple scaling relation of EFermi/N1/3, in which EFermi is the Fermi energy of bulk gold. The transition energy scaling inversely with cluster radius indicates that electronic structure can be well described with the spherical jellium model and further demonstrates that these nanomaterials are multi-electron artificial atoms. Fluorescence from these small metal clusters can be considered protoplasmonic, molecular transitions of the free conduction electrons before the onset of collective dipole oscillations occurring when a continuous density of states is reached. In addition, very strong single molecular Stokes and Antistokes Raman enhancement by fluorescent silver clusters was observed. Pushing to larger sizes, we also created ~ 2nm diameter glutathione encapsulated luminescent gold nanoparticles. Distinct from similarly sized but nonluminescent gold nanoparticles, these 2 nm gold nanoparticles show bright, long lifetime emission but no plasmon absorption. The emission might arise from charge transfer between gold atoms and the thiol ligand. Providing the missing link between atomic and nanoparticle behavior in noble metals, these highly fluorescent, water-soluble gold and silver nanoclusters offer complementary transition energy size scalings at smaller dimensions than do semiconductor quantum dots. The unique discrete excitation and emission and strong Stokes and antistokes Raman enhancement coupled with facile creation in aqueous solution open new opportunities for noble metal nanoclusters as biological labels, energy transfer pairs, and other light emitters in nanoscale electronics.
Advisors/Committee Members: Dickson, Robert M. (Committee Chair), El-Sayed, Mostafa A. (Committee Member), Lyon, Andrew L. (Committee Member), Wang, Zhong Lin (Committee Member), Whetten, Robert L. (Committee Member).
Subjects/Keywords: Nanoparticles; Biocompatible; Nanoclusters; Single molecule; Noble metal; Fluorescent
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APA (6th Edition):
Zheng, J. (2005). Fluorescent noble metal nanoclusters. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/10574
Chicago Manual of Style (16th Edition):
Zheng, Jie. “Fluorescent noble metal nanoclusters.” 2005. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/10574.
MLA Handbook (7th Edition):
Zheng, Jie. “Fluorescent noble metal nanoclusters.” 2005. Web. 15 Jan 2021.
Vancouver:
Zheng J. Fluorescent noble metal nanoclusters. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/10574.
Council of Science Editors:
Zheng J. Fluorescent noble metal nanoclusters. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/10574
Georgia Tech
27.
Darugar, Qusai A.
Surface effects on the ultrafast electronic relaxation of some semiconductor and metallic nanoparticles.
Degree: PhD, Chemistry and Biochemistry, 2006, Georgia Tech
URL: http://hdl.handle.net/1853/11534
► The research presented has been focused on understanding the surface effects on the optical and electronic properties of some metallic and semiconductor nanomaterials. When the…
(more)
▼ The research presented has been focused on understanding the surface effects on the optical and electronic properties of some metallic and semiconductor nanomaterials. When the particle sizes are on the nanometer length scale, a large fraction of atoms in the particles are on the surface. The bonding of the surface atoms being unsaturated could cause trapping and introduce defects that interact with the excited electrons. The effect of the surface on the optical and electronic properties of some semiconductor and metallic nanoparticles is investigated. When the size and shape of nanomaterials change, both the electron density of the excited electrons on the surface and the electronic structure change. Therefore, it becomes important to understand how these changes affect the electronic motion in the particles in order to exploit their full potential in a variety of applications.
Semiconductor nanoparticles studied include cadmium selenide (CdSe) and cadmium sulfide (CdS). Effect of changing CdSe shape and size on optical and electronic properties has been investigated and the ability for the CdS nanoparticles to show optical gain (stimulated emission) in solution at room temperature is reported.
Effect of surface phonon contribution on the exited electron relaxation in copper nanoparticles is investigated. For the particles size smaller than the mean free path of the electrons in the metal, electron-surface phonon coupling becomes an important factor (contribution) for hot electron relaxation. In the thesis presented, it is shown for the first time the size depended electronic relaxation in copper nanoparticles. Fluorescence due to surface plasmon field enhancement is observed for copper nanoparticles to be million times stronger than the fluorescence observed from bulk copper.
Advisors/Committee Members: El-Sayed, Mostafa (Committee Chair), Lyon, Andrew (Committee Member), Orlando, Thomas (Committee Member), Wang, Zhong (Committee Member), Zhang, John (Committee Member).
Subjects/Keywords: Colloidal; Nanoparticles; Nanocrystals; Femtosecond; Pump-probe; Bleach; Dynamics; Simulated emission; Optical gain; CdSe; CdS; CdTe; Copper; Transient
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APA (6th Edition):
Darugar, Q. A. (2006). Surface effects on the ultrafast electronic relaxation of some semiconductor and metallic nanoparticles. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/11534
Chicago Manual of Style (16th Edition):
Darugar, Qusai A. “Surface effects on the ultrafast electronic relaxation of some semiconductor and metallic nanoparticles.” 2006. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/11534.
MLA Handbook (7th Edition):
Darugar, Qusai A. “Surface effects on the ultrafast electronic relaxation of some semiconductor and metallic nanoparticles.” 2006. Web. 15 Jan 2021.
Vancouver:
Darugar QA. Surface effects on the ultrafast electronic relaxation of some semiconductor and metallic nanoparticles. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/11534.
Council of Science Editors:
Darugar QA. Surface effects on the ultrafast electronic relaxation of some semiconductor and metallic nanoparticles. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/11534
Georgia Tech
28.
Nicovich, Philip R.
Widefield fluorescence correlation spectroscopy.
Degree: PhD, Chemistry and Biochemistry, 2010, Georgia Tech
URL: http://hdl.handle.net/1853/33849
► Fluorescence correlation spectroscopy has become a standard technique for modern biophysics and single molecule spectroscopy research. Here is presented a novel widefield extension of the…
(more)
▼ Fluorescence correlation spectroscopy has become a standard technique for modern biophysics and single molecule spectroscopy research. Here is presented a novel widefield extension of the established single-point technique. Flow in microfluidic devices was used as a model system for microscopic motion and through widefield fluorescence correlation spectroscopy flow profiles were mapped in three dimensions. The technique presented is shown to be more tolerant to low signal strength, allowing image data with signal-to-noise values as low as 1.4 to produce accurate flow maps as well as utilizing dye-labeled single antibodies as flow tracers. With proper instrumentation flows along the axial direction can also be measured. Widefield fluorescence correlation spectroscopy has also been utilized to produce super-resolution confocal microscopic images relying on the single-molecule microsecond blinking dynamics of fluorescent silver clusters. A method for fluorescence modulation signal extraction as well as synthesis of several novel noble metal fluorophores is also presented.
Advisors/Committee Members: Dickson, Robert (Committee Chair), Christoph Fahrni (Committee Member), El-Sayed, Mostafa (Committee Member), Lyon, Andrew (Committee Member), Srinivasarao, Mohan (Committee Member).
Subjects/Keywords: Correlation spectroscopy; Super resolution microscopy; Single molecule spectroscopy; Velocimetry; Microfluidics; Fluorescence spectroscopy; Spectrum analysis; Flow visualization; Axial flow; Image analysis
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APA (6th Edition):
Nicovich, P. R. (2010). Widefield fluorescence correlation spectroscopy. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/33849
Chicago Manual of Style (16th Edition):
Nicovich, Philip R. “Widefield fluorescence correlation spectroscopy.” 2010. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/33849.
MLA Handbook (7th Edition):
Nicovich, Philip R. “Widefield fluorescence correlation spectroscopy.” 2010. Web. 15 Jan 2021.
Vancouver:
Nicovich PR. Widefield fluorescence correlation spectroscopy. [Internet] [Doctoral dissertation]. Georgia Tech; 2010. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/33849.
Council of Science Editors:
Nicovich PR. Widefield fluorescence correlation spectroscopy. [Doctoral Dissertation]. Georgia Tech; 2010. Available from: http://hdl.handle.net/1853/33849
Georgia Tech
29.
Wiedemair, Justyna.
Advancing atomic force microscopy-scanning electrochemical microscopy based sensing platforms for biological applications.
Degree: PhD, Chemistry and Biochemistry, 2009, Georgia Tech
URL: http://hdl.handle.net/1853/33960
► Combined atomic force microscopy-scanning electrochemical microscopy (AFM-SECM) is capable of providing simultaneous topographical and electrochemical imaging at sample surfaces. Integration of amperometric biosensors at tip-integrated…
(more)
▼ Combined atomic force microscopy-scanning electrochemical microscopy (AFM-SECM) is capable of providing simultaneous topographical and electrochemical imaging at sample surfaces. Integration of amperometric biosensors at tip-integrated electrodes recessed from the apex of the AFM tip further enhances the versatility of such bifunctional probes. Of particular interest to this work was the detection of adenosine triphosphate (ATP) at a cellular level, since ATP is involved in many biologically relevant processes. There are challenges concerning the integration of biosensors into bifunctional AFM-SECM probes. This thesis focuses on addressing and advancing several of these limitations. Thin insulation layers are important for AFM-SECM based applications to enhance AFM and SECM performance. Plasma-polymerized fluorocarbon membranes are introduced as novel thin film insulation materials for AFM-SECM probes. Insulation layers with a thickness of < 300 nm were found to exhibit excellent insulating properties and satisfying temporal stability for successful application in AFM-SECM experiments. Furthermore new approaches for increasing the electrode area in conventionally focused ion beam (FIB) fabricated AFM-SECM probes were implemented, since enhancement of the current response in conjunction with biosensing experiments is required. Ion beam induced deposition (IBID) was used to generate platinum carbon (PtC) deposits at AFM-SECM probes, thereby successfully increasing the tip-integrated electrode area. PtC composites were thoroughly characterized in terms of their physical and electrochemical properties. Since a high carbon fraction in the PtC composite was inhibiting the charge transfer kinetics at the electrode surface for certain analytes, several pre-treatment strategies were investigated including annealing, UV/ozone treatment, and FIB milling. FIB milling proved to be the most promising procedure improving charge transfer properties at the electrode along with fabrication compatibility at AFM-SECM probes. The last part of this thesis aimed at providing fundamental studies on AFM-SECM application at live epithelial cell monolayers. AFM was used in different imaging modes to characterize the topography of epithelial cells. ATP detection at epithelial cells was achieved with amperometric biosensors combined with non-invasive SECM. Biosensors were further miniaturized at batch-fabricated AFM-SECM probes enabling laterally-resolved detection of ATP at epithelial cells. Additionally, PtC composite materials were evaluated for applicability as transducer platforms for enzymatic biosensors.
Advisors/Committee Members: Mizaikoff, Boris (Committee Chair), Kranz, Christine (Committee Co-Chair), Eaton, Douglas (Committee Member), Fernandez, Facundo (Committee Member), Loeffler, Frank (Committee Member), Lyon, Andrew (Committee Member).
Subjects/Keywords: Adenosine triphosphate; Electrochemistry; Microelectrodes; Biosensors; Atomic force microscopy; Scanning electrochemical microscopy; Scanning probe microscopy; Detectors; Medical instruments and apparatus; Plasma polymerization
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wiedemair, J. (2009). Advancing atomic force microscopy-scanning electrochemical microscopy based sensing platforms for biological applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/33960
Chicago Manual of Style (16th Edition):
Wiedemair, Justyna. “Advancing atomic force microscopy-scanning electrochemical microscopy based sensing platforms for biological applications.” 2009. Doctoral Dissertation, Georgia Tech. Accessed January 15, 2021.
http://hdl.handle.net/1853/33960.
MLA Handbook (7th Edition):
Wiedemair, Justyna. “Advancing atomic force microscopy-scanning electrochemical microscopy based sensing platforms for biological applications.” 2009. Web. 15 Jan 2021.
Vancouver:
Wiedemair J. Advancing atomic force microscopy-scanning electrochemical microscopy based sensing platforms for biological applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2009. [cited 2021 Jan 15].
Available from: http://hdl.handle.net/1853/33960.
Council of Science Editors:
Wiedemair J. Advancing atomic force microscopy-scanning electrochemical microscopy based sensing platforms for biological applications. [Doctoral Dissertation]. Georgia Tech; 2009. Available from: http://hdl.handle.net/1853/33960
. 
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